MS3 Mini - Very low AFRs/Stalling after heat soak
#1
MS3 Mini - Very low AFRs/Stalling after heat soak
Car is a 2001 NBFL 1.6L
Long story short, the car will run, drive & idle perfectly for about an hour of driving.
After that when coming to a stop the rpms drop super low, closed loop idle most of the times will save the car from stalling but the AFRs during the ordial are super low ~10,5.
If it stalls the car has a very hard time starting unless you press gas, then its not certain if it will keep running or die.
Letting the car sit and cool down for 15-20 minutes, starts to behave normally again.
Im new to tuning, but i've done my research before posting, i hope someone can point me to the right direction!
I've checked the obvious but i cant find the culprit!
Attached is the tune & logs of the weird behavior
Thanks guys
Long story short, the car will run, drive & idle perfectly for about an hour of driving.
After that when coming to a stop the rpms drop super low, closed loop idle most of the times will save the car from stalling but the AFRs during the ordial are super low ~10,5.
If it stalls the car has a very hard time starting unless you press gas, then its not certain if it will keep running or die.
Letting the car sit and cool down for 15-20 minutes, starts to behave normally again.
Im new to tuning, but i've done my research before posting, i hope someone can point me to the right direction!
I've checked the obvious but i cant find the culprit!
Attached is the tune & logs of the weird behavior
Thanks guys
Last edited by MarkNode; 08-29-2020 at 12:54 PM.
#4
Your car is set to use the Closed Loop Idle Initial Value table however all entries inside of the table are 0
This will cause the car to stall as the valve closes whenever it tries to enter closed loop idle & send the IAC 0% duty
Also having the closed loop idle setting PID gain slider at 2k is pretty high, running the same PID settings as you I have it set at 500. Around 1k I had issues with the car seeking its target idle speed too hard and stalling even with a tuned closed loop idle table.
This will cause the car to stall as the valve closes whenever it tries to enter closed loop idle & send the IAC 0% duty
Also having the closed loop idle setting PID gain slider at 2k is pretty high, running the same PID settings as you I have it set at 500. Around 1k I had issues with the car seeking its target idle speed too hard and stalling even with a tuned closed loop idle table.
#5
Your car is set to use the Closed Loop Idle Initial Value table however all entries inside of the table are 0
This will cause the car to stall as the valve closes whenever it tries to enter closed loop idle & send the IAC 0% duty
Also having the closed loop idle setting PID gain slider at 2k is pretty high, running the same PID settings as you I have it set at 500. Around 1k I had issues with the car seeking its target idle speed too hard and stalling even with a tuned closed loop idle table.
This will cause the car to stall as the valve closes whenever it tries to enter closed loop idle & send the IAC 0% duty
Also having the closed loop idle setting PID gain slider at 2k is pretty high, running the same PID settings as you I have it set at 500. Around 1k I had issues with the car seeking its target idle speed too hard and stalling even with a tuned closed loop idle table.
#6
Almost 100% yes, a way to confirm this would be to check and see if the car ever enters closed loop idle when it is warming up, I suspect some settings are preventing it from entering closed loop til the car is warmer than usual. The logs indicated nothing except the valve IAC Duty % dropping a ton, which I can only assume is due to a zero'd out closed loop idle table.
I would be surprised if the car didn't stall when it tried to enter closed loop idle with the current setup
I would be surprised if the car didn't stall when it tried to enter closed loop idle with the current setup
#7
Almost 100% yes, a way to confirm this would be to check and see if the car ever enters closed loop idle when it is warming up, I suspect some settings are preventing it from entering closed loop til the car is warmer than usual. The logs indicated nothing except the valve IAC Duty % dropping a ton, which I can only assume is due to a zero'd out closed loop idle table.
I would be surprised if the car didn't stall when it tried to enter closed loop idle with the current setup
I would be surprised if the car didn't stall when it tried to enter closed loop idle with the current setup
#10
Here is a new set of logs
Unfortunately the problem still persists
1. cold start and idle until hot without any changes to the tune, no throttle, no ac etc
2. first drive with closed loop initial values table filled (experimented with the values as i went) everything seemed to be ok!
3. second drive the problem started to appear again, check the logs and you will see that the AFRs keep dropping and at the second half of the drive the RPMs during throttle lift/coasting/stopping drop very low
4. third failed start attempt after stall.
I also attached the latest tune for comparison.
Thanks guys!
Unfortunately the problem still persists
1. cold start and idle until hot without any changes to the tune, no throttle, no ac etc
2. first drive with closed loop initial values table filled (experimented with the values as i went) everything seemed to be ok!
3. second drive the problem started to appear again, check the logs and you will see that the AFRs keep dropping and at the second half of the drive the RPMs during throttle lift/coasting/stopping drop very low
4. third failed start attempt after stall.
I also attached the latest tune for comparison.
Thanks guys!
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